SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6efbbd389c1bfc7b15614cee83ac4e4cec86ca3ad40c82d116de368bb8864d85' 
  AND token = 'Mxm9dW+OzJD3E/1TayBZGXKV7YU+l8UjWQBnkfUNfdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}